I was wondering, how to truck drivers change a flat? I saw an 18-wheeler blow out a tire last week and pull over, then I started thinking, how do they change it? They are so big and heavy, and I can't imagine a Jack could lift up the tralior or the truck.
My only guess is that the wheels themselves can be lifted up individually somehowHow do Truck Drivers Change a flat tire?Most of the axles have double wheels on each side. If one blows, there is enough strength in the other to get the truck to a shop. Drivers cannot change them themselves without a 80 tonne jack and a huge air gun.How do Truck Drivers Change a flat tire?Believe it or not, they call the tire man. And it is for that reason. They are heavy and big. My husband is a truck driver and there has been a few times that I was with him that a tire blew. Be careful not to be to close to the trucks when they do blow a tire. The shreds can bust your windshield real easy. Thats why most drivers don't like cars by their back axles. Its dangerous.How do Truck Drivers Change a flat tire?They can lift one axle at a time then you can change the tire with the rim still bolted to the truck if it's the outside tire. Also if you have a flat on an out side tire on a set of duels you can simply drive onto a block of wood with the inside tire lifting the outside clear of the ground.How do Truck Drivers Change a flat tire?truck drivers normally call tire shops to come to us. If we are at our own shop, each axle lifts separately with a 5 or 10 ton hydrolic jack so it can be serviced much like your own car, just on a much larger scale. I am a tractor trailer driver as well as a tow truck driver.How do Truck Drivers Change a flat tire?i know that when i was in the air force and drove in those big trucks that we would change them ourselves (but i was also in vehicle maintenance so that was our job --- the other people in our group, if they had a flat, we had to stop and change it for them)
For the big rigs you're seeing, the drivers are not allowed to change the tires. The main reason is because they're split-rim wheels and are extremely dangerous when underinflated --- they can easily explode and kill anything in it's trajectory.
Plus, they're huge and heavy - easily weighing 500lbs when inflated, about 300lbs when completely flat (those rims are HEAVY!) so special equipment is needed that is not on the trucks (which is on purpose to an impatient driver does not simply do it himself and get all killed and stuff).
SO - when an 18-wheeler has a flat, they call their roadside assistance (i used to work for Ryder roadside assistance dispatch) which dispatches a service truck to go to them to change it or tow it to the nearest service station to repair/replace the wheel.
and yes, a jack (a very heavy-duty one) can lift the truck and/or trailer enough to do it, it's just too dangerous to do on the side of the road like you would a passenger vehicle.How do Truck Drivers Change a flat tire?To lift one tire isn't such a problem for them as long as they have a strong enough jack(3000-4000 lbs.). The trick about it is that there is no tool to pull the old tire off the rim. They have to use pry bars and litteraly hammer the tire off and the new one on. Then they have to make the rim seal to the tire bead. Most guys simply use a minor explosion like spraying alot of ether in the tire and setting it aflame. then the tire takes its form and is then aired up.How do Truck Drivers Change a flat tire?I assume you are talking about changing a spare?
I am not familiar with split rims. However, I have changed many of the others by myself using a 20 ton bottle jack to lift it and a 3/4 inch drive breaker bar and socket. Sometimes I would have to heat the nuts/studs with a torch in order to break them loose and always had to use a 4 or 5 foot long %26quot;cheater bar%26quot; as an extension on the handle for more leverage. I bet I looked a bit foolish jumping up and down on the pipe. Hehe. Anyway, itt is not a wise practice to pick them up by yourself to place them back on... but if you do it right (face away and lift it behind you) you will be ok.How do Truck Drivers Change a flat tire?We call our company and they call a road service company to come out and fix a flat for us. It can take hours and hours from the time of the call to when they actually get there...How do Truck Drivers Change a flat tire?My man works on semi trailers and the send a truck out to take care of the broken down trucker!How do Truck Drivers Change a flat tire?Like several said, most call the tire guy: a mounted spare is usually too heavy to justify lugging it around all the time -- especially when you consider it would be pretty useless without a jack strong enough to lift one side of the heaviest-laden axle.
For almost all vehicles requiring either a %26quot;Class A%26quot; or a %26quot;Class B%26quot; CDL, compressed air isn't a problem: they've got air brakes and most vehicles in service have a %26quot;quick connect%26quot; for using compressed air remotely (like airhose %26amp; tool).
Most 18-wheelers have a GVWR of 80k lbs and almost never have more than 16k lbs per axle (ordinarily and by law, the load on any single axle cannot exceed 20k lbs).
Usually, the bridge formula governs OTR axle loadings, except some places impose lower limits -- and then there's always the possibility of a permitted overload.
While the actual force required to lift one side of such an axle laded to the legal maximum might be only 10k lbs, most service jacks are rated for at least 12t -- 24,000 lbs -- (but not much more).
The Michelin XZA3 11R-22.5 weighs 119 lbs apiece; the 11R-24.5 weighs 129 lbs apiece -- but you can probably find modern %26quot;normal size%26quot; (not wide-base) tires up to maybe 150 pounds. That's JUST the tire.
A typical 22.5 x 7.5 aluminum wheel weighs 55 lbs; a typical 24.5 x 8.25 steel wheel weighs 86 lbs. I've heard of some roadside service trucks having dollies that let them remove duals without separating them -- but if you're doing it solo, forget it.
If you've got an old spoke-style wheel, split rims and have to deal with inner tubes and flaps (and in some cases, boots), you're looking at more weight and more junk to have to deal with.
I can't count the number of 10.00-20 tires I've changed using a bottle jack and some boards and a pull-handle and socket -- or how many studs I've wrung off or handles I've broken -- or how many mounted tires I've %26quot;broken down,%26quot; swapped-out and built-up: it must be in the high hundreds -- and I didn't do it all that long.
For a white dude, I was pretty danged quick with a hammer (rim mallet), ring tool (when applicable) and spoons (swan-necked bead tools) -- but I got backlogged one day and had to call the tire guy, and he showed me a whole new world of quick!
That's when he became %26quot;my tire guy:%26quot; the only tires I changed after that were the ones I needed changed while he was on another job (and I couldn't wait) or when he was too tired to come out -- he worked as many hours a day as I did, and I wasn't gonna deny him much-needed and well-deserved rest.
Oh -- and you're right about SOME trucks having 1 or more retractable axles; however, that's not an ordinary thing -- and even when a truck has 1 or more retractable axles, it still has axles that aren't retractable.
I've never heard of more than 3 retractable axles on 1 truck; regardless, they were all %26quot;spare axles%26quot; designed to distribute the load for axle-loading compliance: they retracted to keep the tires from wearing out as quickly as they otherwise would.
Freight is a cutthroat business (and usually the victim discovers he was holding the knife used to injure him when the assault occurred -- if you know what I mean).
Oh -- and %26quot;who's to blame%26quot; said it right about lifting the mounted tires. :)
PS: A wide-base tire (also known as a %26quot;Super Single%26quot;) is sometimes used to replace a pair of %26quot;ordinary size%26quot; tires. These, and %26quot;high-flotation%26quot; tires, are larger than %26quot;ordinary size%26quot; tires -- and they use correspondingly larger wheels.
Although an individual high-flotation or wide-base tire is heavier than its common counterpart, and though its associated wheel is heavier than the ordinary, smaller unit, weight savings are realized when wide-base tires are used to replace pairs of %26quot;ordinary size%26quot; tires.
There are disadvantages to wide-base tire usage, but that's well beyond the scope of your question.
No tire that may legally be used on a public roadway is able to hold anywhere close to 200 pounds of air! The internal volume of a typical truck tire is significantly less than 7.5 cubic feet; the air in a properly-inflated tire is compressed to about 90-120 psig.
Rounding WAY up, that's a max of 9.5 atmospheres of absolute pressure. Air weighs roughly 0.00256 lbs per cubic foot at 60 degrees Fahrenheit -- 9.5 times which would be 0.02432 lbs per cubic foot at 60 degrees Fahrenheit for the air in the tire.
However, if it's very cold, we'll have to put extra air in to keep the pressure up. Let's drop the temperature to -140 degrees Fahrenheit: I don't know many people operating trucks in that temperature, but what the heck.
We have to use the Rankine scale to get the ratios, since we're working in Fahrenheit. The short answer is we have to put 62.7 percent more air in the tire to maintain the same pressure (actually a very slight increase).
Doing the math, that gives us 1.627 x 0.02432 = 0.03956864 lbs per cubic foot at -140 degrees Fahrenheit for the air in the tire. Multiply that by a very generous 7.5 cubic feet and you have a %26quot;maximum thoretically possible%26quot; weight of less than 0.300 pounds per tire for %26quot;normal%26quot; (11R22.5, 11R24.5) tires.
Even if you tripled that to allow for the most outrageous outsize possible on a wide base tire, you're looking at less than 9/10 of a pound of air per tire, even at -140F and 120 psig!
